A liquid level sensor in which a first detection electrode and a second detection electrode are provided at a resistor substrate is disclosed in Patent Document 1 (Japanese Patent Application Laid-Open No. 2009-210503) for example. In this liquid level sensor, the liquid level is detected from the electrostatic capacitance detected at the first detection electrode and the electrostatic capacitance detected at the second detection electrode.    [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-210503    [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-218861    [Patent Document 3] Japanese Patent Application Laid-Open No. 2008-524618